Which issue(s) does this change fix?

Why is this change necessary?

We create an instance of a botocore lambda client to interact between the CLI commands and the durable executions emulator. However, if a customer doesn't have any AWS credentials set through any credential provider, API calls using the boto client will fail with Unable to locate credentials.

How does it address the issue?

Adding a set of mock credentials passed to the .create() classmethod. This is only used by the emulator when it creates a lambda client.

What side effects does this change have?

None.

Mandatory Checklist

PRs will only be reviewed after checklist is complete

• Review the generative AI contribution guidelines
• Add input/output type hints to new functions/methods
• Write design document if needed (Do I need to write a design document?)
• Write/update unit tests
• Write/update integration tests
• Write/update functional tests if needed
• make pr passes
• make update-reproducible-reqs if dependencies were changed
• Write documentation

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.